Equations look good when items are properly separated. The main separation is the Medium Mathematical Space: x = 3.
Note: if you are viewing the non-Unicode version math.html of this page then you are in fact seeing midspaces, which are very similar but not exactly the same: (4)/(18) em for medium mathematical spaces versus (1)/(2) en, where 1 em = 2 en. Try out the Unicode version math-unicode.html — and viceversa. You can check out what version this page is in the page title.

The command \raisebox is useful to, surprisingly, raise a little box,

raisedoverloweredand back.

Like \mbox, it puts its content in a text box. It can also be used just for spacing:BV.

Regular text in a formula can be achieved via text font commands like \textrm: 5 to 10, via boxes like \mbox (prevents line breaks): 6 is more than 5, or the AMSmath \text macro (scales like math symbols) basesupersub. The content of an mbox is processed in LaTeX text mode. This allows text font commands, e.g. a switch to sans-serif-bold-italic, or the phonetic alphabet: sfbfit, tipa.

Units should be written upright, either with \mathrm or with macros from the units package, e.g. as simple unit, km, with magnitude, 57 km, with fractional unit, 200 km⁄h, or with a fraction before the units, 3⁄2 km, (7)/(16) s.

limx → ∞f(x) should appear as x → ∞ in italics, and «lim» in plain style. In display mode, a limit must appear below the main symbol:

limx → ∞f(x).

Limits are also used in sums and integrals:

∞⎲⎳i = 1x, ∞⌠⌡0f(x) dx

where the sum’s limits should appear below (i = 1) and above (∞) the ∑. The placement of the integral limits depends on the document class: LaTeX standard classes place them right to the ∫. Limits are shown to the right in inline formulae: ∑∞i = 1x and ∫∞i = 1x.

The placing of limits can be configured with the \limits and \nolimits macros:

Arrays are separated by variable-size brackets: ⎛⎜⎝abcd⎞⎟⎠⎡⎢⎣abcd⎤⎥⎦⎧⎨⎩abcd⎫⎬⎭⟨abcd⟩|||abcd|||which might also differ on right and left ⎛⎜⎝abcd⎞⎟⎠ or use the empty opening ⎧⎨⎩abcd or closing: abcd|||. There are also fixed-size big brackets, e.g. ⟨f⟩.